In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

SA Liberals kick off 2018 pre-selections

The South Australian Liberal Party has opened nominations for pre-selection in 34 of the state's 47 electorates ahead of the 2018 election.

The party says nominations have opened for all 21 current Liberal-held seats, 11 current Labor-held seats and two held by independents.

Advertisements inviting candidates will be run later this week and pre-selection for the remaining 13 seats will open at a later date.

Opposition Leader Steven Marshall says the party is appealing for passionate and hard-working candidates to help build on its strong parliamentary team.

He says the election, which will come after 16 years of Labor government, will be an opportunity for a fresh approach and new direction for the state.

"The state Liberals' vision for South Australia will ensure hard work is rewarded and promote opportunities that have been missing under successive Labor administrations," he said in a statement on Wednesday.

"A Liberal government will provide responsible leadership and deliver a clear pathway to recovery and success."